1. Field of the Invention
The present invention relates to a laminated ink jet recording head that is formed by laminating at least a first cover member, a spacer, and a second cover member and that is fixed to a passage unit having nozzle openings and common ink chambers, the first cover member having piezoelectric vibrators fixed to a surface thereof, the spacer forming pressure generating chambers therein, the second cover member having communicating holes communicating with the common ink chambers and a nozzle plate.
2. Description of the Prior Art
Using ink droplets to form dots on a recording medium, ink jet recording heads can implement extremely high resolution printing by reducing the size of each ink droplet. However, in order to print data efficiently, the number of nozzle openings must be increased, and when piezoelectric vibrators are used as an ink droplet jetting source, the downsizing of the piezoelectric vibrators is an essential consideration.
By the way, an ink jet recording head using flexural vibration as an actuator, the actuator unit, which includes a first cover member having piezoelectric vibrators fixed to a surface thereof, a pressure generating chamber forming board forming pressure generating chambers, and a second cover member, can be made of ceramics. As a result, no adhesive is required to bond these members to one another. On the other hand, a passage unit that supplies ink to the actuator unit and jets the ink pressured by the pressure generating chambers in the form of ink droplets must have a number of nozzle openings, each being formed with high accuracy to a diameter of about several tens of .mu.m. As a result, a thin plate made of metal is usually used and is bonded to the actuator unit through an adhesive.
However, if the nozzle openings are pitched at a small interval, e.g., at an interval of about 210 .mu.m, a bonding area becomes extremely narrow. As a result, the nozzle openings are clogged due to the adhesive flowing into the nozzle openings and ink leakage occurs, which in turn has caused the problem of impaired ink jetting performance.